In general, wrinkles is a part of natural aging, which is caused by repeated muscular contractions for a long period of time. Skin aging is broadly classified into intrinsic aging, or natural aging and extrinsic aging. The natural aging is difficult to be regulated, because it is caused by genetic factors, but extrinsic aging is easy to be regulated artificially, because it is caused by environmental factors. Thus, studies on the prevention of extrinsic aging have been continued, and particularly, studies on the prevention of wrinkle formation resulting from extrinsic photoaging, which progresses due to long-term exposure to UV radiation, have received attention (Gilchre st B. A., J. Am. Acad. Dermatol., 1989:21:610-613).
The clinical characteristics of photoaging, that is, extrinsic skin aging, are that the skin becomes rough and loses elasticity, irregular pigmentation occurs and deep wrinkles increase. Particularly, it has been found that photoaging has a great effect on the formation of wrinkles on the face and head, which are important objects of beauty, and thus, as fundamental studies on the development of anti-wrinkle cosmetic products, studies on photoaging and wrinkle formation in human skin or animal models have been actively conducted. With respect to photoaging and wrinkle formation, the results of studies on changes in basic physiological metabolisms, such as collagen synthesis and degradation, have been reported to date (Lavker R. M., Blackwell science Inc., 1995:123-135).
External factors influencing skin aging include wind, temperature, humidity, cigarette smoke, environmental pollution and UV radiation, and particularly, aging caused by UV radiation is called “photoaging”. When the skin is exposed to a large amount of UV radiation, a high concentration of reactive oxygen species are produced in the skin to damage the enzymatic and non-enzymatic antioxidant defense systems of the skin. For this reason, collagen, that is, the main protein of skin tissue, is remarkably reduced, and matrix metalloproteinase-1 (MMP-1) has an important effect on the reduction of collagen. Matrix metalloproteinase-1 (MMP-1) is an enzyme involved in the degradation of the extracellular matrix and the basement membrane, and it has been reported that the activity of matrix metalloproteinase-1 in the skin is increased due to UV radiation to remarkably degrade collagen, and thus matrix metalloproteinase-1 has an important effect on collagen degradation and plays a very important role in wrinkle formation (Sim G. S., Kim J. H et al., Kor. J. Biotechnol. Bioeng., 2005:20(1):40-45).
Some of active ingredients for anti-wrinkle, which have been developed to date, have problems in that they cannot be used as cosmetic materials, are very unstable and are not easy to deliver to the skin, such that a special stabilizing system and delivery system are required, and the effect thereof on the reduction of skin wrinkles is not visible. For this reason, interest in skin-protecting agents containing retinoid has recently been increased. Currently, retinoid is used as a means for solving photoaging phenomena, such as wrinkles resulting from sunlight, skin thickening, skin drooping and a decrease in skin elasticity. However, retinoid has a problem in that it is a very unstable compound, which is sensitive to UV light, moisture, heat and oxygen such that a chemical change therein easily occurs. In attempts to solve this problem, studies focused on developing effective components derived from natural resources have been conducted.